Pivot actuated sleeve valve

ABSTRACT

A valve assembly has a valve body and a fluid passage through the valve body with an inlet end and an outlet end. A valve seat is defined within the fluid passage. A sleeve is axially slidable within the fluid passage and has an upstream end, a downstream end, and an axial flow passage in communication with the inlet end and the outlet end of the fluid passage. A valve stem is pivotally mounted at a stem pivot spaced radially from the fluid passage. The valve stem is actuable to slide the sleeve between an open position with the downstream end spaced from the valve seat and a closed position with the downstream end borne against the valve seat to selectively control fluid flow through the flow passage to the outlet end.

RELATED APPLICATION DATA

[0001] This patent is related to co-pending U.S. provisional PatentApplication Serial No. 60/284,592, which was filed on Apr. 18, 2001.

FIELD OF THE INVENTION

[0002] The invention is generally related to fluid valves, and moreparticularly to a sleeve valve that is pivot actuated.

BACKGROUND OF THE INVENTION

[0003] Conventional fluid valves are typically of the rotary stem orsliding stem type. A rotary valve for fluid service incorporates arotary shaft held in a cylinder of a valve body. The shaft, uponrotation, either aligns a radial port of the shaft with a fluid port ofthe valve body to open a valve passage, or mis-aligns the ports to closethe valve passage. In operation, the typical rotary valve stem mustrotate about 90 degrees relative to the valve body between the fullyopen and closed positions. Other types of rotary valve designs areavailable that utilize alternative geometries requiring shaft rotationthat is less than 90 degrees, such as three way or angled ball valves.Rotary valves typically employ seals, and often bearings, between therotary shaft and valve body to prevent fluid from leaking from the valvebody between the shaft and its cylinder. This significant movementcauses substantial wear to both the seals and, if present, the bearings.Thus, the bearings and seals of such a valve must be replaced over time.The seals, in order to function properly, also add friction between thecylinder and stem. Substantial force is therefore necessary to overcomethe seal friction and to rotate the stem.

[0004] A sliding stem valve operates similar to a piston and has a valveplug on a stem that slides linearly within a cylinder of a valve body.The valve plug bears against a seat or closes a passage when closed, andis spaced from the seat or clears the passage when open. Again, thevalve stem and valve plug must move relative to the cylinder of thevalve body a significant distance between the fully open and closedpositions. Sliding stem valves typically employ seals, and often guides,between the stem and valve body to prevent fluid from leaking from thevalve body between the stem and its cylinder. The significant linearmovement of the valve body causes wear on the seals, and if present, thebearings, and thus the seals and bearings must be replaced over time.The seals also create friction that must be overcome in order to movethe linear stem valve between the open and closed positions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Exemplary sleeve valves constructed in accordance with theteachings of the present invention are described and explained ingreater detail below with the aid of the drawing figures in which:

[0006]FIG. 1 is a perspective view of one example of a sleeve valveconstructed according to the teachings of the present invention.

[0007]FIG. 2A is a longitudinal cross section taken along line II-II ofthe valve shown in FIG. 1 and showing the valve in an open position.

[0008]FIG. 2B is a cross section of the valve shown in FIG. 2 andshowing the valve in a closed position.

[0009]FIG. 3 is a side view in partial cross section of one example of avalve stem and sleeve arrangement constructed according to the teachingsof the present invention.

[0010]FIG. 4 is a top view of the valve stem and sleeve arrangement ofFIG. 3.

[0011]FIG. 5 is a side view in partial cross section of another exampleof a valve stem and sleeve arrangement constructed according to theteachings of the present invention.

[0012]FIG. 6 is a side view in partial cross section of another exampleof a valve stem and sleeve arrangement constructed according to theteachings of the present invention.

[0013]FIG. 7 is a side view in partial cross section of another exampleof a valve stem and sleeve arrangement constructed according to theteachings of the present invention.

[0014]FIG. 8 is a side view in partial cross section of another exampleof a valve stem and sleeve arrangement constructed according to theteachings of the present invention.

[0015]FIG. 9A is a side view in partial cross section of another exampleof a valve stem and sleeve arrangement constructed according to theteachings of the present invention.

[0016]FIG. 9B is an end view of the valve stem and sleeve arrangementshown in FIG. 9A.

[0017]FIG. 10A is a side view in partial cross section of anotherexample of a valve stem and sleeve arrangement constructed according tothe teachings of the present invention.

[0018]FIG. 10B is a side view in partial cross section of the valve andsleeve arrangement of FIG. 10A during actuation.

[0019]FIG. 11 is a side view in partial cross section of the valve shownin FIG. 2 and having an alternative valve plug configuration.

[0020]FIG. 12 is a side view in partial cross section of the valve shownin FIG. 2 and having another alternative valve plug configuration.

[0021]FIG. 13 is a side view in partial cross section of the valve shownin FIG. 2 and having another alternative valve plug configuration.

[0022]FIG. 14 is a side view in partial cross section of the valve shownin FIG. 2 and having alternative sleeve and valve plug configurations.

[0023]FIG. 15 is a side view in partial cross section of one example ofa valve stem pivot arrangement constructed according to the teachings ofthe present invention.

[0024]FIG. 16 is a side view in partial cross section of one example ofa valve stem pivot arrangement constructed according to the teachings ofthe present invention.

[0025]FIG. 17 is a side view in partial cross section of one example ofa valve stem pivot arrangement constructed according to the teachings ofthe present invention.

[0026]FIG. 18 is a side view in partial cross section of one example ofa valve stem pivot arrangement constructed according to the teachings ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] It is one object of the present invention to provide a valve thatsolves one or more of the problems described above for the rotary valveand linear stem valve. It is another object of the present invention toprovide a fluid valve that utilizes a pivoting action in order toactuate the valve. It is a further object of the present invention toprovide a sleeve valve that incorporates such a pivoting action. It is astill further object of the present invention to provide a fluid valvewherein mechanical advantage can be easily incorporated and manipulatedto provide the valve seating force as necessary.

[0028] Referring now the drawings, FIG. 1 illustrates one example of asleeve valve 20 in perspective view and constructed according to theteachings of the present invention. The sleeve valve 20 is generallyillustrated in FIGS. 1, 2A, and 2B and has a valve body 22 and apivoting valve stem 24 for actuating the valve between open and closedpositions as described below. The valve stem 24 is pivoted by anactuator 26 about a stem pivot 27. The actuator 26 is coupled to anupper stem section 28 of the valve stem 24 above the stem pivot 27. Theactuator 26 can vary considerably and yet fall within the scope of thepresent invention. In one example, the actuator 26 has a reciprocatingrod 30 that can move axially according to movement of a diaphragm,electric motor, linkage, or the like, as desired for a particularapplication.

[0029] The valve body 22 generally has an elongate hollow section 32defining a fluid passage 34 that extends through and is defined by aninterior surface 35 within the valve body between an inlet end and anoutlet end of the body. The valve body 22 defines an inlet 36 to thepassage 34 and an outlet 38 from the passage. The inlet end and theoutlet end of the valve body 22 each include a mounting shoulder orflange 40 and 42, respectively, for securing the valve 20 in placewithin a desired apparatus or system. Both the inlet and outlet flanges40 and 42 can vary in size and configuration as needed for a particularuse of the sleeve valve 20.

[0030] A portion of the hollow section 32 of the valve body 22 definesan annular bulge 44 extending radially outward from the hollow section32. The bulge 44 produces an increased diameter section 45 within thevalve passage 34 that encompasses a stationary valve plug 46. The valveplug 46 is positioned axially within the passage 34 to longitudinallycoincide with the bulge 44 and passage section 45. The valve plug isheld stationary within the passage 34 by one or more webs 58 or othersecuring device that extend between the valve body and valve plug. Inthe disclosed example of FIGS. 1, 2A, and 2B, the valve plug 46 and webs48 are integrally formed as a unitary part of the valve body 22 withinthe passage 34. Alternatively, the valve plug 46 can be secured in placesuch that it can be removed as desired. In one example, the valve plug46 can be secured by removable fasteners to ribs or webs of the valvebody. In a further alternative, the valve plug 46 can itself be threadedin place onto a portion of the valve body 22. In some embodiments of thevalve 20, it may be desirable to remove the valve plug 46 to service theplug or plug components for wear, or to remove and replace the valveplug with another plug having different characteristics. Removablyinstalling the plug 46 will permit such service or replacement.

[0031] The size of the valve plug will determine the size of the bulge44 and increased diameter passage section 45. The general crosssectional flow area of the passage 34 downstream of the valve plug(nearer the outlet 38) and the cross sectional flow area of the passagewithin the increased diameter section 45 (around the plug 46) ispreferably greater than or equal to the cross sectional flow area of thepassage upstream of the valve plug (nearer the inlet 36). This is doneto insure that fluid flow is not restricted by the valve body, but onlyat the desired throttling area about the sleeve and plug. The bulge 44and passage section 45 provide the additional cross sectional flow areafor the passage 34 around the valve plug 46 to accomplish this goal.

[0032] The valve body 22 also has an integral stem housing 50 extendingradially outward from the hollow section 32. The stem housing 50 has abase 52 either integrally formed as part of the hollow section 32 of thevalve body 22, or, if desired, attached and fluidly sealed thereto. Thestem housing 50 extends radially outward and terminates at a pivot end54 opposite the base 52. The stem housing 50 defines the stem pivot 27for the stem 24 at or near the pivot end 54 as described below. The stemhousing 50 is therefore necessarily substantially rigid to maintain afixed pivot point for the stem.

[0033] The sleeve valve 20 also includes a slidable sleeve 60 in theform of an annular or cylindrical tube with an interior surface 61 thatdefines a flow passage through the sleeve. The sleeve 60 is receivedcoaxially within the passage 34 and is adapted for sliding into and outof engagement with the stationary valve plug 46. In general, the valvestem 24 has a lower stem section 62 that is pivotally connected to thesleeve 60 at a drive connection 63. The lower stem section 62 drives thesleeve axially within the passage 34 between an open position as shownin FIG. 2A and a closed position as shown in FIG. 2B. The lower stemsection 62 is pivotally coupled to the sleeve 60 for driving the sleeveaxially within the passage 34. The lower stem section 62 passes throughan opening 64 defined within the base 52 and the hollow section 32. Theopening 64 can be a linear slot permitting only linear, axial movementof the lower stem section 62. Alternatively, the opening 64 can be anopening through the hollow section 32 that is shaped to coincide withthe entire footprint of the base 52 of the stem housing 50. The openingcan also be other sizes and shapes as desired.

[0034] As shown in FIG. 2A, the sleeve 60 is positioned in the openorientation. The sleeve 60 has a downstream end 66 generally facing theoutlet 38 of the passage 34, and has an upstream end 68 generally facingthe inlet 36 of the passage. In the open orientation, the downstream end66 is spaced a distance from the stationary valve plug 46 permittingfluid to freely pass through the passage 34 and the sleeve 60, flowingaround the valve plug and out the outlet 38 of the passage. FIG. 2Billustrates the sleeve 60 in the closed orientation wherein thedownstream end 66 abuts and seals against the stationary valve plug 46.A seal 69 can be provided on either the sleeve downstream end 68 or thevalve plug 46. Fluid is prevented from passing to the outlet 38 of thepassage 34 by the valve plug 46, the sleeve 60, and seal 69.

[0035] If desired, one or more sleeve seals 70 can provide a fluidtight, or at least a fluid inhibiting, seal between the interior surface35 of the passage 34 and an exterior surface 72 of the sleeve 60.Depending upon the longitudinal length of the sleeve 60, the sleeve canprevent fluid from passing through the opening 64 into an interior 74 ofthe stem housing 50, whether in the open or the closed orientation. Afluid tight seal 70 can be used to prevent fluid from entering theinterior 74 of the housing 50. If the sleeve seals 70 are simply fluidinhibiting seals, some fluid may pass into the interior 74 of the stemhousing. With such a construction, it is preferable to further sealbetween the stem 24 and the pivot end 54 of the stem housing, asdescribed in greater detail below, in order to prevent any fluid fromescaping the valve 20. With either type of seal 70, it is desired thatno process fluid leak downstream to the outlet 38, bypassing the sleeve60, until the sleeve is released from the plug 46. Various types ofsleeve seals 70 are known to those of ordinary skill in the art and canbe utilized without departing from the scope of the invention.

[0036] FIGS. 3-10B illustrate a number of alternative embodiments forthe drive connection 63 between the lower stem section 62 and the sleeve60. Referring first to FIGS. 3 and 4, one example of the driveconnection 63 is illustrated. In this example, the exterior surface 72of the sleeve includes a socket or depression 80 formed therein. Thelower stem section 62 includes a rounded end 82 that closely follows thecontour of the socket 80 and is received therein. The rounded end 82 andsocket 80 therefore form a ball and socket joint permitting pivotalmovement of the lower stem section 62 relative to the sleeve 60 as thesleeve is driven axially along the passage 34 by the stem 24. Therounded end 82 on the lower stem section 62 can be integrally providedon the stem or can be a ball or element having a semispherical surfacethat is attached to the stem.

[0037]FIG. 5 illustrates another alternative embodiment of the driveconnection 63 between the lower stem section 62 and the sleeve 60. Inthis disclosed example, the exterior surface 72 of the sleeve 60includes a tapered opening 84. The interior surface 61 of the sleeve 60includes a socket 88 that is co-axially aligned with the tapered opening84. Together, the combined socket 88 and tapered opening 84 passcompletely through the sleeve 60. A ball 90 is disposed on the lower endof the lower stem section 62 in this example. Again, the ball 90 can beattached in any suitable manner to the lower stem section 62, or can beintegrally provided thereon. For example, a discrete ball 90 can have athreaded stud 92 that is received in a corresponding opening in thelower stem section 62. The drive connection 63 illustrated in FIG. 5essentially provides a ball and socket joint adjacent the interiorsurface 61 of the sleeve 60 and permits the lower stem section 62 topivot within the tapered opening 84.

[0038]FIG. 6 generally shows a drive connection 63 similar to that shownin FIG. 3. In most instances, the pivot action of the stem 24 willproduce a travel arc at the lower end of the lower stem section 62.Hence, the vertical (with reference to the drawing orientation) positionof the stem will vary during operation. Since the sleeve 60 isstationary in the vertical direction, this travel arc must beaccommodated.

[0039]FIG. 6 also illustrates a lower stem section 262 with a blind bore264 formed axially into the lower end. A Belville washer 266 ispositioned in the blind bore 264 and biases a ball 268 downward. Theball is permitted to move vertically within the blind bore as the stempivots to accommodate this travel arc of the lower stem section 262.

[0040]FIG. 7 shows another example of a drive connection 63 adapted toaccommodate for the travel arc of the lower stem section. In thisexample, a lower stem section 270 has a lower end coupled with a link272 pivotally connected via a first pivot 274 at one end to the lowerend of the stem section 270. The link 272 is also pivotally connected ata second pivot 276 to a sleeve 278. The sleeve 278 has a trough 280formed therein permitting the link 272 and stem section 270 to movevertically relative to the sleeve 278. In this example, the link 272 iscoupled to the lower end of the stem section by a fixed link 282. Thelink 282 is threadingly received in the lower end of the stem section270 and carries the first pivot 274. The first pivot 274 canalternatively be carried directly on the lower end of the stem section270, if desired. As will be evident to those having ordinary skill inthe art, other constructions and arrangements are also possible foraccommodating the travel arc of the stem (see FIGS. 10A and 10B below).

[0041]FIG. 8 illustrates another alternative example of a driveconnection 63. In this example, a clevis 94 is secured to the exteriorsurface 72 of the sleeve 60 in a suitable manner. As disclosed in thisexample, the clevis 94 has a threaded stud 96 extending therefrom thatis received in a corresponding bore provided in the exterior surface ofthe sleeve. A pivot pin 98 extends transversely through the lower stemsection 62 near the bottom end. The pivot pin 98 is pivotally secured toa portion of the clevis 94. The lower stem section 62 pivots about theclevis 94 at the pin 98. To accommodate the travel arc of the stem 24,the clevis pivot pin openings can be slotted to permit vertical travelof the lower end of the stem relative to the sleeve.

[0042]FIGS. 9A and 9B illustrate another alternative example of a driveconnection 63 between the sleeve 60 and the lower stem section 62. Inthis example, a wishbone shaped element or section 100 is provided on aportion of the sleeve and is oriented in a plane generally normal to thesleeve axis. The wishbone section 100 can alternatively be formedintegral as a part of the sleeve. The wishbone in this example issecured to or formed integral with a portion of the interior surface 61of the sleeve 60. The wishbone section 100 can also provided on theexterior surface 72, if certain flow characteristics within the sleeveare of importance. The wishbone section 100 extends partly around thecircumference of the sleeve. Located centrally relative to the wishbonesection 100 and extending upward relative to the sleeve is a trunnion102 pivotally connected to the lower end of the lower stem section 62.The trunnion 102 can also be in a form similar to the clevis 94 and canbe attached by a pivot pin (not shown) to the lower stem section 62forming the pivotable drive connection 63. The trunnion pin openings canbe slotted to accommodate the stem travel arc.

[0043] As will be evident to those of ordinary skill in the art, thedrive connection 63 at the lower stem section 62 and sleeve 60 canutilize many different constructions and components. The intendedfunction of the drive connection 63 is to permit the lower stem section62 to pivot relative to the sleeve so that the stem 24 can pivot and yetcan linearly drive the sleeve within the passage 34. Also, each of thedisclosed examples can vary from the specific form shown in thepertinent FIGS. 3-9B and yet fall within the scope of the invention.

[0044]FIGS. 10A and 10B further illustrate the variety of constructionsthat can be used to form the drive connection and to accommodate thetravel arc of the stem. FIG. 10A illustrates a valve 20 having a valvebody 300 similar to the valve body shown in FIG. 1. A stem housing 302is provided extending from a portion of the body 300. A sleeve 304 isreceived in a passage 306 similar to the valve in FIG. 1. A valve stem308 is connected at a top end 310 to an actuator (not shown) fordrivingly pivoting the stem. A lower end of the stem 308 is pivotallycoupled at a first pivot 312 via a clevis 314 to the sleeve 304. A bootor seal 316 is sealingly secured around a portion of the lower stem 308and is clamped between portions of the stem housing 302 to form aprocess fluid barrier within the housing 302.

[0045] A generally mid-portion of the stem 308 bears against a fulcrumor roller 318 held on an interior wall 320 of the housing. A biasingelement such as a coil spring 322 biases the stem against the fulcrum atall times. The fulcrum provides a stem channel 324 in its exteriorsurface to laterally retain the stem in position. The fulcrum can eitherbe fixed and provide a low friction bearing surface for the stem, or canbe a roller bearing that is free to rotate about a pivot 326.

[0046] As shown in FIG. 10B, as the stem is driven, it pivots or wobblesabout the fulcrum 318, and at the same time rolls or slides verticallyalong the fulcrum. The clevis 312 and first pivot 314 travel along alinear path. The stem 308 therefor will rise and fall slightly relativeto the fulcrum 318. The stem can slide along the fulcrum within thechannel 324 during operation to accommodate the travel arc of the stem.In the previously described examples, the lower end of the stem providedthis relative vertical movement between stem and sleeve. In the exampleof FIGS. 10A and 10B, the stem pivot 27 provides this relative movement.

[0047] FIGS. 11-14 disclose several different examples of the valve plugand sleeve seal arrangement. Special service valve plugs, such as fornoise attenuation, cavitation protection, or “soft seat” (TEFLON®) sealprovision can require such service or replacement. The valve plug 46 asdescribed above can be removably installed in the passage 34 permittingservice or replacement of such valve designs. FIG. 11 shows a valve 20with a valve plug 46 having an added soft seat construction. The plug 46includes a replaceable tip 400 having a plastic or elastomeric seat 402received over the upstream end of the plug 46. The seat 402 is held inplace on a retainer 404 by a removable fastener 408. The seat materialcan be selected to meet certain material standards and/or tight seatingcharacteristics.

[0048]FIG. 12 shows an alternative replaceable tip 410 having a seat 412of a different configuration held in place by the fastener 408. Thetapered seat 412 may be desired to provide better or different processfluid flow characteristics.

[0049]FIG. 13 shows another example of an alternative valve plugincluding an attachment fitting or end 420. The plug end 420 has acylindrical configuration with a center bore 422, an annular wall 424,and an exterior surface 426. The exterior surface 426 has a diametersuch that it can be received and closely fit within the interior of thesleeve 60. A first set of radial openings 428 are provided and spacedapart circumferentially around the plug end 420. A second set ofopenings 430 are also provided circumferentially around the plug end420, but longitudinally spaced upstream from the first set 428.Additional sets of openings can also be provided as desired. Theopenings 428 are exposed and opened first during travel of the sleeve 60toward the inlet end (open position). Process fluid can first pass onlythrough the openings 428. As the sleeve is moved further toward the openposition, the next set or sets of openings 430 become sequentially open.The sleeve and plug can be design to only expose the radial openingswhen the sleeve is in the fully open position. Alternatively, the outletend of the sleeve can release and move further away from the plug 46when in the open position to permit free flow through the sleeve andaround the entire plug 420. By this example, various flowcharacteristics can be achieved as desired, depending upon the positionof the sleeve relative to the plug.

[0050]FIG. 14 shows a similar plug end and sleeve configuration exceptthat radial openings 440 and 442 are formed in the sleeve near itsoutlet end. A plug fitting or end 444 in this example is a solidcylinder adapted to be received in and closely fit the interior of thesleeve. The solid plug will sequentially open or close off the openings440 and 442, depending upon the sleeve position within the passage.

[0051] FIGS. 15-18 illustrate a number of different disclosed examplesof the stem pivot 27 between the valve stem 24 and the pivot end 54 ofthe stem housing 50. In each of the these examples, the valve stem 24 isintended to pivot about a point defined generally at the pivot end 54 ofthe stem housing 50. This stem pivot 27 is preferably sealed so that anyprocess fluid passing into the interior 74 of the stem housing 50 doesnot weep or leak from the valve body 22. It is also preferable that thestem pivot 27 between the valve stem 24 and the stem housing 50 be africtionless or a low friction joint. The valve stem 24 in any of thedisclosed examples herein can either be a single integral stemincorporating both the lower stem section 62 and upper stem section 28,or can be formed of two separate stem sections interconnected with oneanother.

[0052] As illustrated for the stem pivot 27 disclosed in FIG. 15, thevalve stem 24 has a radial bulge or an enlarged diameter portionrelative to the remainder of the stem. The bulge has a partial circularcontour forming a pivot ball 104 on the stem. The stem housing 50 has afrusto-conical shape terminating at an annular upwardly extending lip110. An inwardly extending annular flange 112 is disposed just below thetop of the lip 110 and defines a stem opening 114 into the stem housing.The flange 112 also has a top surface that forms a ledge 113. In thisexample, the inward facing surface of the flange 112 is curved to form asocket or seat for the ball 104 of the stem 24.

[0053] An O-ring seal 116 rests on the ledge 113 within the interior ofthe lip 110 to provide a fluid seal at the pivot joint. Further in thisexample, a bearing 118 is received over the top of the lip 110 andsandwiches the O-ring seal between the bearing 118 and the ledge 113.The upper stem 28 extends upward through openings in the O-ring seal 116and the bearing 118. A bonnet or cap 120 also has a tapered opening 121through which the upper stem section 28 passes. The cap 120 also has adisk portion 122 that bears against the bearing 118 and has a dependingflange portion 124 that, in the disclosed example, threadingly engagesan exterior surface 126 of the lip 110. The cap 120 can be secured inany desired manner to the housing 50, such as, for example, by aplurality of bolts, latches, or the like. The cap 120 and bearing 118securely hold the stem pivot 27 in an assembled condition and preventthe stem 24 from inadvertently being removed or ejected from the valve20. The bearing 118 and the interfacing surface 113 or seat permit thestem 24 to pivot about the ball 104. The frusto-conical shape of thestem housing interior 74 and the cap tapered opening 121 permit thelower stem to pivot freely through its full range of travel within thestem housing.

[0054]FIG. 16 illustrates another alternative embodiment of a stem pivot27 for the valve stem 24 and stem housing 50. In this example, the stem24 again includes a ball 104 positioned near the pivot end of the stemhousing. In this example, the stem housing 50 again is frusto-conicalshaped and has an annular inward facing flange 112 and upturned lip 110similar to the prior example. This example also discloses a cap 120 anda bearing 118 similar to the prior example. However, in this example, alower bearing 130 is provided and has an opening 132 therethrough forreceiving the stem 24. The lower bearing opening 132 defines a socket onits interior surface, wherein the socket has a shape that corresponds tothe shape of the ball 104 of the stem. The socket is constructed andarranged so that the ball 104 rests and is supported by the socketsurface.

[0055] The lower bearing 130 is supported on the ledge 113 of the flange112. An O-ring 136 or packing is received within a groove 137 formed inan upper surface 138 of the bearing 130. The O-ring 136 provides a fluidseal around the ball 104 of the stem. The upper bearing 118 is againprovided resting on a top surface of the lip 110 and sandwiches theO-ring 136 and the lower bearing 130 between the ledge 113 and the upperbearing. The bonnet or cap 120 is essentially identical in constructionto the prior disclosed example and is received over the lip 110 and issecured in place by mechanical threads between the cap and the exteriorsurface 126 of the lip.

[0056] To provide a further fluid-tight seal at the stem pivot 27, abellows or boot 140 can be received over a portion of the lower stemsection 62. In this example, the bellows 140 has a plurality ofconvolutions 142 to permit movement of the bellows. The boot or bellows140 can also be of a generally flat or non-convoluted and flexibleconstruction, if desired. An upper end of the bellows 140 can be securedeither to the stem 24 near the ball 104 or to the lower bearing with thelower stem section simply received through the bellows. A lower end ofthe bellows can tightly seat or seal against the lower stem section 62.The bellows 140 can be provided as an elongate boot substantiallycovering the lower stem section 62 to protect the lower stem sectionfrom contact with process fluids passing through the sleeve valve 20that may otherwise cause damage to the material of the stem or tocomponents of the stem pivot 27. Alternatively, the bellows 140 can beprovided as a shorter length boot to simply prevent process fluid fromleaking past the stem pivot 27 at the stem housing pivot end 54.

[0057]FIG. 17 illustrates one alternative example of a portion of thestem pivot 27 for providing a fluid-tight seal. In this example, thedisclosed element 130 has an alternative, shorter length bellows 150.The element 130 can be a washer sandwiched beneath the lower bearingdescribed above with the bellows carried by or captured by the element130. The element 130 can alternatively be the lower bearing. The element130 can be a flexible metal disc that is received over a portion of thestem near the ball 104. The disc can be welded to a portion of the stemand/or can be welded to a portion of the ledge 113 of the flange 112.Alternatively, the element 130 as a metal disc can be appropriatelysandwiched between pivot region components and be borne and sealedagainst the stem. The bellows 150 in this example includes only one ortwo convolutions 152 permitting some movement of the lower stem sectionabout the pivot ball 104 while maintaining a fluid-tight seal. A lowerend of the bellows 150 is disposed a distance from the ball 104 but notnearly as far down the lower stem section as the bellows 140 in theprior example. The lower end of the bellows 150 can again provide afluid-tight seal around the lower stem section. An O-ring or a thickenedsection of material for an elastomeric boot can provide the fluid tightseal. Alternatively, the boot or bellows 150 can be formed of a metallicmaterial, wherein the lower end of the bellows 150 can be welding orotherwise affixed around the lower stem section 62. Similarly, the upperend of the bellows 150, if formed of an elastomeric material, can besandwiched between the lower element 130 and the ledge 113 to provide aseal when the stem pivot 27 is assembled. If a metallic bellows is used,the bellows upper end can be welded or otherwise affixed to the element130 to form a seal. The shorter length bellows 150 can be substitutedfor the elongate bellows 140 in the prior example with all othercomponents of the stem pivot 27 remaining the same.

[0058] As discussed above, the stem 24 can either be a single integralunit or can be formed of separate upper and lower stem sections. FIG. 18illustrates such a two-piece stem 24 in one disclosed example. FIG. 18also illustrates another alternative embodiment of a stem pivot 27including a stand alone bearing 160 coupled to a bellows 150, asdescribed above in the disclosed example of FIG. 17. The two-piece stemand bellows 150 can be utilized with any of the above described examplesas well as with the alternative example of FIG. 18.

[0059] In FIG. 18, the disclosed upper stem section 28 can be formed ofone type of material and the lower stem section 62 can be formed of adifferent type of material, wherein the two discrete stem sections areinterconnected to one another. In the disclosed example, the upper stemsection 28 includes a threaded stud 162 extending from its lower endthat is received in a complementary threaded bore 164 in the upper endof the lower stem section 62. In some examples, process fluid “P”passing through the sleeve valve 20 may come in contact with the lowerstem section 62 in the interior 74 of the stem housing 50, as shown. Theprocess fluid may be of a caustic composition that can damage or degradecertain materials, such as certain metals or plastics. The lower stemsection 62 can therefore be made from a suitable material that is notharmed by the process fluid “P”, though such material may be quiteexpensive, difficult to work with, and/or relatively hard to obtain. Thetwo-piece stem design illustrated in FIG. 18 permits the upper stemsection 28 to be manufactured from a material that is different from thelower stem section and less expensive, easier to work with and/or morereadily available.

[0060] Also in the example of FIG. 18, a small bellows or boot 150similar to that disclosed in FIG. 17 is received over the stem. A lowerend of the bellows 150 sealingly engages the lower stem section 62. Anupper end of the bellows 150 is suitably attached to the bearing 160that rests on and is affixed to the ledge 113 of the inwardly extendingflange 112 and within the lip 110 at the pivot end 54 of the stemhousing 50. In this example, a seal such as an O-ring 166 can provide afluid-tight seal between the outer perimeter of the bearing 160 and theledge 113 and lip 110 of the stem housing 50. The bearing 160 definesthe stem pivot 27 for the stem 24. Again, the stem pivot 27 canalternatively be assembled similar to the embodiments disclosed in FIGS.15 and 16 utilizing an upper bearing and bonnet or cap. The bellows 150can alternatively be adhered to a washer, a flange, or a part of thestem housing 50 as well. Also as noted above, the bellows need not be anelastomeric convoluted bellows, but instead can be a flexible metalseal, either as a convoluted part, a flexible metal disc, or the like.The bearing 160 reflects the shape of one possible example of a flexiblemetallic seal shape.

[0061] As will be evident to those of ordinary skill in the art, thevarious constructions of the stem pivot 27 and the joint componentsbetween the stem 24 and stem housing 50 can vary considerably and yetfall within the scope of the present invention. Certain examples aredisclosed herein although other examples are permissible.

[0062] As will be evident to those having ordinary skill in the art, thebellows configuration and materials, the bearing shapes and materials,the stem lengths, shapes, and materials, the valve body sizes, shapes,and materials, and other components can all vary and yet fall within thescope of the invention. Metal, graphite, TEFLON or other bearing typescan be utilized as desired. Metal or plastic valve bodies can be used aswell. Stainless steel for the valve body, stem, and plug components isoften preferable for its durability, strength, workability, and otherdesirable characteristics.

[0063] Although certain sleeve valve examples have been disclosed anddescribed herein in accordance with the teachings of the presentinvention, the scope of coverage of this patent is not limited thereto.On the contrary, this patent covers all embodiments of the teachings ofthe invention fairly falling within the scope of the appended claims,either literally or under the doctrine of equivalents.

What is claimed is:
 1. A valve assembly comprising: a valve body; a fluid passage through the valve body having an inlet end and an outlet end; a valve seat defined within the fluid passage; a sleeve axially slidable within the fluid passage and having an upstream end, a downstream end, and an axial flow passage in communication with the inlet end and the outlet end of the fluid passage; and a valve stem pivotally mounted at a stem pivot spaced radially from the fluid passage, the valve stem being actuable to slide the sleeve between an open position with the downstream end spaced from the valve seat and a closed position with the downstream end borne against the valve seat to selectively control fluid flow through the flow passage to the outlet end.
 2. A valve assembly according to claim 1, further comprising: a fluidly sealed stem housing extending radially from the valve body and housing both the stem pivot and a portion of the valve stem.
 3. A valve assembly according to claim 1, further comprising: a linear actuator coupled to an upper stem section for actuating the valve stem to slide the sleeve.
 4. A valve assembly according to claim 1, wherein one end of the valve stem is coupled to the sleeve at a joint and wherein the stem pivot accommodates relative axial movement of the valve stem as the sleeve slides within the fluid passage.
 5. A valve assembly according to claim 4, wherein the joint includes a clevis attached to the sleeve and a pin pivotally coupling the valve stem and the clevis.
 6. A valve assembly according to claim 4, wherein the joint includes a wishbone mounted within a groove extending partly around a circumference of the sleeve, the wishbone having a radially extending trunnion and a pin pivotally coupling the valve stem to the trunnion.
 7. A valve assembly according to claim 4, wherein the stem pivot comprises: a roller fixed for rotation to a portion of the valve body and having a stem channel formed therein wherein the valve stem rides in the stem channel; and a biasing element adapted to bias the valve stem into the stem channel of the roller.
 8. A valve assembly according to claim 7, wherein the stem pivot is housed within a stem housing extending from the valve body.
 9. A valve assembly according to claim 1, wherein the valve stem has a lower stem section coupled to the sleeve at a joint that accommodates relative movement between the joint and the stem pivot in an axial direction relative to the valve stem as the sleeve slides within the fluid passage.
 10. A valve assembly according to claim 1, wherein the valve stem is coupled to the sleeve at a joint that accommodates relative movement between the joint and the stem pivot in an axial direction relative to the valve stem as the sleeve slides within the fluid passage, wherein the joint is a ball and socket arrangement between the sleeve and a distal end of the lower stem section.
 11. A valve assembly according to claim 10, wherein the ball and socket arrangement comprises: a socket formed in the sleeve; and a ball provided on a distal end of a lower stem section.
 12. A valve assembly according to claim 11, wherein the socket is formed in an exterior surface of the sleeve and has a depth sufficient to permit the ball on the lower stem section to move radially relative to the sleeve.
 13. A valve assembly according to claim 11, wherein the socket is on an interior surface of the sleeve, the lower stem section passes through a tapered opening in the sleeve in communication with the socket, and the ball is fixed to the distal end of the lower stem section.
 14. A valve assembly according to claim 11, wherein the ball is received in a blind bore formed in the distal end of the lower stem section and is biased axially outward from and can move axially within the blind bore, and wherein the socket is formed in an exterior surface of the sleeve.
 15. A valve assembly according to claim 1, wherein the valve stem is coupled at one end to the sleeve at a joint that accommodates relative movement between the joint and the stem pivot in an axial direction relative to the valve stem as the sleeve slides within the fluid passage, wherein the joint includes a linkage arrangement.
 16. A valve assembly according to claim 15, wherein the linkage arrangement comprises: a fixed link extending from a distal end of the valve stem; and a drag link pivotally coupled at one end to the fixed link and pivotally coupled at an opposite end to the sleeve.
 17. A sleeve valve assembly comprising: a valve body; a fluid passage through the valve body having an inlet end and an outlet end; a valve seat defined within the fluid passage; a stem housing extending radially from the valve body; a sleeve axially slidable within the fluid passage and having an upstream end, a downstream end, and an axial flow passage in communication with the inlet end and the outlet end of the fluid passage; a stem pivot housed within the stem housing; and a valve stem pivotally mounted at the stem pivot and partly extending through the stem housing, the valve stem being actuable to slide the sleeve between an open position with the downstream end spaced from the valve seat and a closed position with the downstream end borne against the valve seat to selectively control fluid flow through the flow passage to the outlet end.
 18. A valve assembly according to claim 17, wherein the stem pivot is defined at a pivot end of the stem housing spaced from the fluid passage.
 19. A sleeve valve assembly according to claim 17, wherein the stem pivot further comprises: a pivot ball carried on the valve stem; a ledge formed in a pivot end of the stem housing; and a cap removably received over the pivot end of the stem housing defining a bearing region and pivotally capturing the pivot ball between the cap and the ledge in the bearing region.
 20. A sleeve valve assembly according to claim 19, wherein the stem pivot further comprises: a fluid tight seal captured within the bearing region.
 21. A sleeve valve assembly according to claim 20, wherein the fluid tight seal is one of an O-ring and a packing.
 22. A sleeve valve assembly according to claim 19, wherein the stem pivot further comprises: at least one bearing captured within the bearing region and borne against the pivot ball of the valve stem.
 23. A sleeve valve assembly according to claim 19, wherein the stem pivot further comprises: an upper bearing and a lower bearing captured within the bearing region and borne against opposite sides of the pivot ball of the valve stem.
 24. A sleeve valve assembly according to claim 19, wherein the stem pivot further comprises: a bellows seal tightly coupled at one end to the valve stem and captured at an opposite end within a part of the bearing region.
 25. A sleeve valve assembly according to claim 18, wherein the stem pivot further comprises: a flexible metal disc seal tightly coupled at one end to the valve stem and captured at an opposite end within a part of the stem pivot near the pivot end of the stem housing.
 26. A sleeve valve assembly comprising: a valve body defining a fluid passage with an inlet end and an outlet end; a valve seat within the fluid passage; a stem housing extending radially from the valve body; a sleeve axially slidable within the fluid passage and having an axial flow passage in communication with the inlet end and the outlet end of the fluid passage; and a valve stem partly extending through the stem housing and being pivotable about a stem pivot to slide the sleeve between an open position and a closed position to selectively control fluid flow through the flow passage to the outlet end, wherein one end of the valve stem is coupled to the sleeve at a joint and wherein the stem pivot accommodates relative movement of the valve stem in an axial direction of the valve stem as the sleeve slides within the fluid passage.
 27. A sleeve valve assembly comprising: a valve body defining a fluid passage with an inlet end and an outlet end; a valve seat within the fluid passage; a stem housing extending radially from the valve body; a sleeve axially slidable within the fluid passage and having an axial flow passage in communication with the inlet end and the outlet end of the fluid passage; and a valve stem partly extending through the stem housing and being pivotable about a stem pivot to slide the sleeve between an open position and a closed position to selectively control fluid flow through the flow passage to the outlet end, wherein one end of the valve stem is coupled to the sleeve at a joint that accommodates relative movement between the joint and the stem pivot in an axial direction relative to the valve stem as the sleeve slides within the fluid passage. 